Reply
 
Thread Tools Search this Thread Display Modes
 
Old 02-18-2016, 12:50 PM   #1
Rivet Master
 
KJRitchie's Avatar

 
2008 25' Classic
Wichita Falls , Texas
Join Date: Nov 2012
Posts: 4,222
Running AC off Batteries

Just viewed this video from Gone with the Wynns where they ran their AC off their lithium batteries with their full solar deployed.

My question is, why did the Magnum monitor show such high amp usage. With just the fan running prior to compressor start it show 27amp then when the AC kicks it ramped up to over 70amps. Most RV ACs are connected to 20amp breakers.

http://www.gonewiththewynns.com/off-...age-1#comments

Kelvin
__________________

__________________
2008 Classic 25fb "Silver Mistress"
2015 Ram 2500 6.7L Cummins. Crew Cab, 4x4, Silver
KJRitchie is offline   Reply With Quote
Old 02-18-2016, 01:35 PM   #2
Rivet Master
 
HowieE's Avatar
 
1991 34' Excella
Princeton , New Jersey
Join Date: Aug 2003
Posts: 6,814
Images: 12
The high current was DC current @ 13 volts from the batteries not AC draw @110 volts AC of the AC unit.

Yes it can be done but at a very high cost
__________________

__________________
WBCCI 12156 AIR 3144 WACHUNG TAC NJ6
2004 Excursion 4x4
1991 34 ft. Excella +220,000 miles, new laminated flooring, new upholstery, new 3200 lbs axles

HowieE is offline   Reply With Quote
Old 02-18-2016, 03:17 PM   #3
Rivet Master
Commercial Member
 
lewster's Avatar
 
Vintage Kin Owner
Naples, FL , Hood River, OR
Join Date: Dec 2005
Posts: 7,282
Running AC off Batteries

Kelvin,

Many folks get confused by amperage draws when comparing a load at 120VDC vs. the same load at 12VDC.

OHM's Law says that power (watts) is equal to volts X amps. Any appliance has one rating for power measured in watts. A typical blower motor for a roof A/C uses about 300 watts.

At 120VAC, this translates to 300/120 or 2.5 amps. That same 300 watt load at 12VDC is 300/12 or 25 amps. The additional draw is probably inverter inefficiency.

If the compressor kicked in, the Magnum would be showing over a150 amp draw AT THE BATTERIES.

You can safely figure a 10:1 ratio to convert amperage loads from AC into DC. A significant number of folks have been opting for the Magnum MSH3012-M Hybrid inverter/ charger when they have been installing solar and lithiums, as this combination allows them to operate their roof A/C solely from their battery bank for 2-5 hours, depending on the size of their lithium pack and all day with a single 2000 watt generator.


Lew Farber
RVIA/RVDA Nationally Certified Master Tech
ABYC Certified Master Marine Electrician
Master Tech Energy Systems, Inc.
AM Solar Certified Installation Center*AMS Lithium Batteries
Lifeline AGM Batteries**Magnum Inverters
541-490-6357
__________________
Lew Farber...ABYC Certified Master Marine Electrician...RVIA Certified Master Tech ...AM Solar Authorized Installation Center...AIRSTREAM Solar & Electrical Specialist...Micro Air 'Easy Start' Sales and Installations
lewster is offline   Reply With Quote
Reply


Currently Active Users Viewing This Thread: 1 (0 members and 1 guests)
 
Thread Tools Search this Thread
Search this Thread:

Advanced Search
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are Off
Refbacks are Off


Similar Threads
Thread Thread Starter Forum Replies Last Post
Where to move batteries inside 23d. Upgrading to AGM batteries. Eyeballs Electrical - Systems, Generators, Batteries & Solar 29 01-08-2016 10:54 AM
Running air conditioner off solar and batteries DavisBurns Sprinter and B-van Forum 29 07-17-2014 04:27 PM
2 batteries outside and two batteries inside timmaah Electrical - Systems, Generators, Batteries & Solar 14 08-25-2011 08:18 AM
Running furnace with just batteries tslanier On The Road... 17 10-17-2006 03:03 PM
Batteries..All about batteries FrankR Batteries, Univolts, Converters & Inverters 0 07-17-2002 10:05 PM


Virginia Campgrounds

Reviews provided by




Copyright 2002- Social Knowledge, LLC All Rights Reserved.

All times are GMT -6. The time now is 04:24 AM.


Powered by vBulletin® Version 3.8.8 Beta 1
Copyright ©2000 - 2017, Jelsoft Enterprises Ltd.

Airstream is a registered trademark of Airstream Inc. All rights reserved. Airstream trademark used under license to Social Knowledge LLC.